Photochemical Aging of Secondary Organic Aerosols Generated from the Photooxidation of Polycyclic Aromatic Hydrocarbons in the Gas-Phase
Language
EN
Article de revue
This item was published in
Environmental Science and Technology. 2015-04-22, vol. 49, n° 9, p. 5407-5416
English Abstract
Aging processes of secondary organic aerosol (SOA) may be a source of oxygenated organic aerosols; however the chemical processes involved remain unclear. In this study we investigate photochemical aging of SOA produced ...Read more >
Aging processes of secondary organic aerosol (SOA) may be a source of oxygenated organic aerosols; however the chemical processes involved remain unclear. In this study we investigate photochemical aging of SOA produced by the gas-phase oxidation of naphthalene by hydroxyl radicals and acenaphthylene by ozone. We monitored the SOA composition using a high-resolution time-of-flight aerosol mass spectrometer (HR-AMS). We initiated SOA aging with UV photolysis alone and with OH radicals in the presence or absence of light and at different NOx levels. For naphthalene, the organic composition of the particulate phase seems to be dominated by highly oxidized compounds such as carboxylic acids, and aging data may be consistent with diffusion limitations. For acenaphthylene, the fate of oxidized products and the moderately oxidized aerosol seem to indicate that functionalization reactions might be the main aging process were initiated by the cumulative effect of light and OH radicals.Read less <